EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our reports included in this Form 10-K, into the Company's previously filed Registration Statements File Nos. 333-07809, 333-44025, 333-45027, 333-52793, 333-69621 and 333-89361. ARTHUR ANDERSEN LLP Chicago, Illinois March 23, 2000